All gave yells, for they were thoroughly frightened. They were pitched together in a heap, and held tight to one another as they went down, first a distance of fifteen or twenty feet and then twice further. "We are in water!" gasped Shep, when he could speak. The water was up to their ankles, but speedily it reached their knees. At last, when the downward movement had come to an end, the boys drew long breaths and tried to gaze around them. They were in a mass of brushwood, and this brushwood seemed to be floating on the water. All was pitch dark around them, for they had not come down straight, but in something of a zig-zag fashion. "Well, of all things!" came from Whopper. "Are we going down to the center of the earth?" "It looks like it." answered Giant, with a groan. "One thing seems to be certain, fellows---we are not meant to get those deer." "That looks to be true," answered Snap. "This is about as bad as being down that hollow tree," said Shep. He was more than glad that he was not alone. Having recovered their breath a little, the young hunters tried to decide upon what would be the best thing to attempt next. "We have got to get out, that is all there is to it," said Snap. "Well, I am willing," said Whopper, gravely. "See any stairs around?" asked Giant. "Maybe Snap has spotted an elevator," said Whopper, with a grin. "If so, Snap, press the button by all means." "I don't think this is any laughing matter," said the leader of the gun club. "No more do I," answered Shep, quickly. "The sooner we get out of this hole the better." "We are moving again!" ejaculated Giant, and all felt that he was right. The whole mass of brushwood floated off on something of an underground stream, carrying the boys with it. The movement continued for a distance of at least two hundred feet and then the bushes became stationary. As it was still pitch dark around them, Snap lit a match and set fire to a dry bush. By the light, they saw they were in a hollow that was not unlike a cave in the mountain. At their feet ran the stream that had carried them forward, disappearing under some overhanging rocks. On all sides were rocks and dirt, with here and there a decayed tree root, showing that they were not very far under the earth's surface. "Here's an adventure," was Shep's comment. "We must be careful, or we'll bring down that dirt above us and be buried alive." "We are about buried alive now," said Giant. "I'd give a good bit to be out of this hole." Stepping from the brushwood, the boys made their way to the dirt and rocks beyond. By this time each had a kind of a torch, so the place was fairly well lighted. Walking back a distance, they saw where the smoke curled to---through the shaft down which they had fallen so unceremoniously. But the top of the shaft was hidden from their view.